Mechanistic study of the stabilization of dentin-bonded restorative interfaces via collagen reinforcement by multi-acrylamides.

Hydrolytically and enzymatically-stable multi-acrylamides have been proposed to increase the long-term durability of dental adhesive interfaces as alternatives to methacrylates. The aim of this study was to investigate the mechanical and biochemical properties of experimental adhesives containing multi-functional acrylamides concerning collagen reinforcement and metalloproteinases (MMP) activity. Multi-functional acrylamides, TMAAEA (Tris[(2-methylaminoacryl) ethylamine) and DEBAAP (N,N-Diethyl-1,3-bis(acrylamido) propane), along with the commercially available DMAM (N,N-dimethylacrylamide) (monofunctional acrylamide) and HEMA (2-Hydroxyethyl methacrylate) (monofunctional methacrylate - control) were tested for stability against enzymatic hydrolysis by cholesterol esterase/pseudocholinesterase (PC/PCE) solutions for up to 30 days.

Revisiting gas-chromatography/mass-spectrometry molar response factors for quantitative analysis (FID or TIC) of glycosidic linkages in polysaccharides produced by oral bacterial biofilms.

Methylation analysis was performed on methylated alditol acetate standards and Streptococcus mutans extracellular polymeric substances (EPS) produced from wild-type and Gtf knockout strains (∆GtfB, ∆GtfB, and ∆GtfD). The methylated alditol acetate standards were representative of glycosidic linkages found in S. mutans EPS and were used to calibrate the GC-MS system for an FID detector and MS (TIC) and produce molar response factor, a necessary step in quantitative analysis.

The potential use of glycosyl-transferase inhibitors for targeted reduction of S. mutans biofilms in dental materials.

Streptococcus mutans is the primary oral caries-forming bacteria, adept at producing "sticky" biofilms via the synthesis of insoluble extracellular polysaccharides (EPS), catalyzed by glucosyltransferases (GTFs). To circumvent the use of broad-spectrum antibiotics to combat these bacteria, this study sought to modify existing EPS-targeting small molecules with the ultimate goal of producing anti-biofilm polymer surfaces specifically targeting S. mutans.

Solvation role of dimethyl sulfoxide on the interaction with dentin bonding systems after 30 months.

Objectives: To determine whether DMSO could serve as an effective pretreatment to improve the mechanical properties and minimize the degradation of the adhesive interface, through the degree of conversion (DC) and bond strength to dentin of different categories of dentin bonding systems (DBSs) after 30 months.

Methods: DMSO (0, 0.5, 1, 2, 5, 10 vol%) were incorporated into four categories of DBSs: Adper Scotchbond Multipurpose (MP), Adper Single Bond 2 (SB), Clearfil SE Bond (CSE) and Adper Scotchbond Universal (SU).

Differential analysis of the dentin soluble proteomic.

Objectives: To perform a differential analysis of the dentin soluble proteomic and assess the effects of tissue health state and protocol for protein extraction. We hypothesized the dentin soluble proteomic varies according to the tissue physiopathological state (intact vs. caries-affected) and protocol used to extract its proteins.

Two-year randomized clinical trial of different restorative techniques in non-carious cervical lesions and MMP activity in gingival crevicular fluid.

Objectives: To evaluate different restorative techniques for non-carious cervical lesions (NCCLs) and the activity of matrix metalloproteinases (MMPs) in gingival crevicular fluid.

Materials And Methods: Two hundred restorations were performed in 50 patients using resin composite restorative system without (I) and with selective enamel conditioning (II) and resin-modified glass-ionomer cement without (III) and with EDTA pretreatment (IV). Gingival crevicular fluid samples were collected in 15 patients.

Profile of a 10-MDP-based universal adhesive system associated with chlorhexidine: Dentin bond strength and in situ zymography performance.

The incorporation of functional monomers and proteolytic inhibitors into adhesive systems have shown to be promising strategies to improve the longevity of adhesive restorations. The aim of this study was to evaluate the long-term bonding performance and anti-gelatinolytic effect of a 10-MDP-based universal adhesive system applied in combination with 2% chlorhexidine digluconate (CHX). For that, this study assessed the resin-dentin bond strength and the in situ gelatinolytic activity profile at the adhesive interface at initial and after 6 month of storage.

Biochemical and immunohistochemical identification of MMP-7 in human dentin.

Objectives: Matrix metalloproteinases (MMPs) are dentinal endogenous enzymes claimed to have a vital role in dentin organic matrix breakdown. The aim of the study was to investigate presence, localization and distribution of MMP-7 in sound human dentin.

Methods: Dentin was powdered, demineralized and dissolved in isoelectric focusing buffer.

How proteolytic inhibitors interact with dentin on glass-fiber post luting over 6 months.

Objectives: Enzyme inhibitors minimize the degradation of unprotected collagen of dentin promoted by matrix metalloproteinases (MMPs) and cysteine cathepsins (CCs). As the evidence of their effect on the root canal is limited, this study aimed to evaluate the role of EDTA, chlorhexidine and E-64 as antiproteolytic agents on the bond strength (BS) of glass-fiber posts in root canals.

Materials And Methods: Ninety-six bovine roots were distributed in groups for each time point (n = 8).

Sodium Trimetaphosphate as a Novel Strategy for Matrix Metalloproteinase Inhibition and Dentin Remineralization.

The effect of sodium trimetaphosphate (STMP) as an antiproteolytic and remineralizing agent on demineralized dentin was evaluated in vitro. The inhibitory potential of STMP at 0.5, 1.

Dynamic Influence of pH on Metalloproteinase Activity in Human Coronal and Radicular Dentin.

The aim of this study was to evaluate the effect of pH on the activation of matrix metalloproteinases (MMPs) of human coronal (CD) and radicular dentin (RD). CD and RD were pulverized to powder, and proteins were extracted with 1% phosphoric acid. The extracted proteins and the demineralized powder were separately incubated in the following solutions: 4-aminophenylmercuric acetate (control) or a buffer solution at different pHs (2.

Role of Proteolytic Enzyme Inhibitors on Carious and Eroded Dentin Associated With a Universal Bonding System.

Objectives: The aim of this study was to evaluate the effect of proteolytic inhibitors on the bond strength of a universal adhesive system (etch-and-rinse mode) applied to artificial carious and eroded dentin.

Methods: Ninety molars were prepared and randomly divided into three groups according to the substrate: N, no challenges; ACD, artificial carious dentin simulation and ERO, artificial erosion simulation with orange juice. All groups were redivided into three subgroups according to the dentin pretreatment: W, water; CHX, 2% digluconate chlorhexidine; and E-64 (trans-epoxysuccinyl-L-leucylamido-[4-guanidino] butane), 5 μM E-64 inhibitor.

Comparative bonding ability to dentin of a universal adhesive system and monomer conversion as functions of extended light curing times and storage.

Objectives: The purpose of this in vitro study was to evaluate the bonding ability and monomer conversion of a universal adhesive system applied to dentin as functions of different curing times and storage. The results were compared among a variety of commercial adhesives.

Materials And Methods: Flat superficial dentin surfaces were exposed on human molars and assigned into one of the following adhesives (n = 15): total-etch Adper Single Bond 2 (SB) and Optibond Solo Plus (OS), self-etch Optibond All in One (OA) and Clearfil SE Bond (CSE), and Scotchbond Universal Adhesive in self-etch mode (SU).

Effect of a one-step self-etch adhesive on endogenous dentin matrix metalloproteinases.

Degradation of the hybrid layer created in dentin by dentin adhesives is caused by enzyme activities present within the dentin matrix that destroy unprotected collagen fibrils. The aim of the present study was to evaluate the effect of a one-step self-etch adhesive system on dentinal matrix metalloproteinases 2 and 4 (MMP-2 and MMP-9, respectively) using in situ zymography and an enzymatic activity assay. The null hypothesis tested was that there are no differences in the activities of dentinal MMPs before and after treatment with a one-step adhesive system.

Co-distribution of cysteine cathepsins and matrix metalloproteases in human dentin.

It has been hypothesized that cysteine cathepsins (CTs) along with matrix metalloproteases (MMPs) may work in conjunction in the proteolysis of mature dentin matrix. The aim of this study was to verify simultaneously the distribution and presence of cathepsins B (CT-B) and K (CT-K) in partially demineralized dentin; and further to evaluate the activity of CTs and MMPs in the same tissue. The distribution of CT-B and CT-K in sound human dentin was assessed by immunohistochemistry.

Phosphoric acid concentration affects dentinal MMPs activity.

Objectives: To evaluate whether the concentration of phosphoric acid (PA) has an effect on the proteolytic activity of sound human demineralized dentin. It is hypothesized that the activity of matrix-bound and extracted enzymes depends on the PA concentration used to demineralize dentin.

Methods: One-gram aliquots of mid-coronal human dentin powder were demineralized with 1wt%, 10wt% and 37wt% PA.

Chlorhexidine inhibits the activity of dental cysteine cathepsins.

The co-expression of MMPs and cysteine cathepsins in the human dentin-pulp complex indicates that both classes of enzymes can contribute to the endogenous proteolytic activity of dentin. Chlorhexidine (CHX) is an efficient inhibitor of MMP activity. This study investigated whether CHX could also inhibit cysteine cathepsins present in dentin.

The influence of time and cement type on push-out bond strength of fiber posts to root dentin.

The bond strength of fiber posts luted with resin cements was evaluated after two storage times in different regions of a post space. A total of 40 single-rooted human teeth were endodontically treated and prepared for cementation of fiber posts (White Post DC). In groups 1 and 3 (G1 and G3, respectively), posts were luted with RelyX ARC, whereas the posts in groups 2 and 4 (G2 and G4, respectively) were luted with RelyX Unicem.

Water sorption and solubility of different calcium hydroxide cements.

Objectives: Calcium hydroxide cements have been largely used in deep cavities due to their abilities to stimulate dentin formation. However, their resistance can be relatively low and their solubility relatively high, in many instances. This study evaluated water sorption and solubility of different calcium hydroxide cements, in order to show alterations that may reduce their effectiveness.

Glass ionomer cements and their role in the restoration of non-carious cervical lesions.

Glass ionomer based materials are clinically popular in several areas of restorative dentistry, but restoration of cervical lesions has proven particularly successful. Various etiologies, conformations, locations and structural characteristics make non-carious cervical lesions more challenging to adhesive restorative procedures and marginal seal in the long run. Due to their characteristics, glass ionomer cements (GICs) have precise indication for these cases.